1. Technical Field
The present invention relates to a transistor array substrate and in particular to a thin film transistor array substrate and method for manufacturing the same.
2. Related Art
Thin film transistor array substrates have been widely used in display applications such as liquid crystal display (LCD), electrophoretic display (EPD), and organic light emitting diode (OLED) display.
Taking the application in LCD for an example, a conventional thin film transistor array substrate includes a substrate, a metal gate layer formed on the substrate, a gate insulating layer formed on the metal gate layer, a source/drain layer formed on the gate insulating layer, an amorphous indium gallium zinc oxide (a-IGZO) layer formed on the source/drain layer, a protective layer formed on the a-IGZO layer and a pixel electrode formed on the protective layer.
However, in the above thin film transistor array substrate, the protective layer is directly formed on the a-IGZO layer, and because the protective layer is usually made of silicon oxide which easily cause the problem of leakage current. Thus, the application of such thin film transistor array substrate is limited.
Therefore, there is a desire to avoid producing the leakage current and improve the performance of the thin film transistor array substrate.